The subject matter herein relates generally to surface mount header connectors for mating engagement with plug connectors.
Connector systems typically include plug connectors mated with corresponding receptacle connectors to form a connector assembly. For example, automobile wiring systems typically include such electrical connectors. The plug connector is mated into a shroud of the header connector. The header connector is in turn mounted on a circuit board along a contact interface. At least some known receptacle connectors are right angle receptacle connectors wherein the plug connector is mated in a direction that is parallel to the contact interface between the header connector and the circuit board. Each of the plug assembly and the header assembly typically includes a large number of electrical contacts, and the contacts in the header assembly are electrically and mechanically connected to respective contacts in the plug assembly when the header assembly and the plug assembly are engaged.
Surface mount header connectors provide a number of advantages over through-hole mounted header connectors. In addition to offering cost and process advantages, surface mounting allows for a reduced footprint for the header connector and thus saves valuable space on a circuit board or permits a reduction in size of the circuit board. When the header connector is surface mounted to a circuit board, solder tails extend from one side of the header connector in an angled manner for surface mounting to a circuit board. The large number of contacts presents manufacturing and assembly challenges in fabricating the header connector, as well as installation problems during surface mounting of the header connector to the circuit board.
For example, it is desirable for surface mounting that the solder tails of the header connector are coplanar to one another for mounting to the plane of a circuit board. Achieving coplanarity with a large number of contacts, however, is difficult due to manufacturing tolerances over a large number of contacts. Sometimes additional solder paste is utilized to compensate for tolerances of the contacts or for misalignment of the contacts during assembly of the header connector. The use of additional solder paste, particularly on systems having tight pitches between contacts is problematic as seepage can cause bridging or electrical shorting. Additionally, over a large number of header connectors, the incremental cost of the increased amount of solder paste per header connector can be significant, and non-planarity of the contacts with respect to the plane of the circuit board may negatively affect the reliability of the header connector. Depending upon the degree of non-planarity of the solder tails, some of the contacts may be weakly connected or not connected to the circuit board at all, either of which is an undesirable and unacceptable result.
A need remains for a header connector that may be mounted to a circuit board in a reliable manner with the contacts achieving coplanarity.